The present invention relates to a reinforcing grid to support and level mortar used in setting tile.
In setting tile on a wall or floor a layer of mortar is applied to the supporting surface and the individual tiles then adhered to the mortar. In the conventional process, a reinforcing structure, such as metal lath or expanded metal, is attached to the supporting surface by nails or screws such that the entire surface to be tiled is covered. Mortar is then applied to the entire surface and trowelled into the reinforcing structure. Redwood strips approximately 3/8 inch thick are then worked or floated into the mortar at intervals across the surface. The mortar is then leveled to a uniform depth by means of a screed which rests on the strips and smooths the mortar to a depth equal to the thickness of the strips. The strips are removed and mortar trowelled into the recesses left by the strips. The mortar is then allowed to set up before the tiles are set in place on it.
In the conventional process the mortar is reinforced and, when applied to a wall, supported by the metal lath or expanded metal immediately adjacent the supporting surface. The exposed surface of the mortar protrudes beyond the reinforcing structure and in the case of a wall, due to the effect of gravity, may tend to slump or sag. Thus, the consistency of the mortar must be carefully controlled or the mortar surface will have to be smoothed with a trowel after the mortar is floated with the screed and before the tiles are set. If the mortar is loose and the surface slumps after it is floated, it is a time-consuming and painstaking process to smooth the surface, so that it is completely flat when the tiles are set in place.
A further disadvantage of the conventional method is that the mortar must be allowed to set up and become stiff enough to support the tiles. Since the individual tiles must be positioned and then pressed against the mortar to insure an adequate bond, the mortar must be stiff enough to stay in place under the pressure of the tile. If the mortar has not been allowed to set up enough, it will be displaced by the pressure and extruded around the edges.
When tiles are set in a floor, a scaffold of boards must be erected over the mortar to allow the tile setter to gain access to the mortar surface without displacing it with his own weight. As the work progresses, the scaffolding must be shifted and the mortar smoothed where ever the boards have contacted it.